1. Field of the Invention
The present invention relates to the field of aeronautics, and more particularly to the construction of aircrafts (e.g., civil airplanes, gliders and model airplanes) with an arresting hook for a landing onto a suspended cable.
2. Description of the Prior Art
One group of such aircrafts is represented by the manned airplanes having an arresting hook for engagement with the cable of a cable landing device (here a term “cable” is understood any flexible element as a rope, a cable, a chain, ets.).
The cable landing system (SU No. 1837038, Int.Cl.7 B 64 F 1/02, 30.08.90) includes a manned aircraft with an arresting hook into the fuselage nose section, and a cable is suspended between two jib cranes situated at a landing position. The arresting hook has a grip portion.
Before a landing the aircraft flies into the cable with the angle of attack beyond stall, providing almost vertical aircraft position with the help of an engine thrust. After a moment of landing by means of engagement of the grip portion of the arresting hook with the cable, the aircraft is decelerated and comes to stop. The aircraft becomes suspended at the nose section to the cable with the tail unit downwards.
The aircraft with the such system of the cable landing has disadvantages including:
a) Engines with the total thrust exceeding an aircraft weight;
b) A complex control system of the aircraft;
c) Additional fuel for a complex landing maneuver;
d) A pilot of the highest qualification;
e) High strength of the fuselage.
Most types of aircrafts, including civil airplanes, glides and unmanned airplanes, do not meet these requirements, and therefore are unsuitable for such cable landing technique.
However, the cable landing device applied in this system is suitable to use without any changes, or with significant simplifications for the landing of model airplanes, gliders and unmanned airplanes using this invention.
Another cable landing system (J. H. BRODIE, U.S. Pat. No. 2,488,050, U.S. Cl. 244/110, Nov. 15, 1949) is equipped with a elevated runway. Along this runway a trolley can move with a catching sling across and below the runway. The aircraft has an arresting hook with a grip portion. Before a landing the hook extends above the aircraft by its grip portion. The aircraft flies under the catching sling for the landing by engagement of the grip portion with the catching sling. After engagement the aircraft is decelerated by braking force of the trolley and comes to stop.
This aircraft has a support device which transmits braking force to the aircraft along the line passing through the center of gravity of the aircraft. For this purpose the axis of rotation of the arresting hook is located transversely of the aircraft on a moveable support. Before the landing the center of gravity of the aircraft is calculated, and the support is moved with a drive (controlled by the pilot) so, that the axis would pass through the center of gravity of the aircraft. As a result of engagement, braking force is applied from the catching sling to the arresting hook and passes through the center of gravity of the aircraft, and therefore, there is no any pitching moment (M) in the course of flight braking. Therefore, the aircraft retains practically a level position all over the period of flight braking.
The disadvantages of this aircraft includes complexity and cost of the aircraft with a support device, a difficult piloting due to a support motion operation with a preliminary calculation of the center of gravity, and the weight of equipment aboard the aircraft. Another disadvantages are low reliability (there is probability of a flight accident because of incorrect setting of the support) and narrow field of application of the cable landing, especially for the light unmanned aircrafts.